This invention relates to an implantable prosthesis, namely a penile prosthesis designed to overcome erectile impotence.
The prior art includes several different penile prosthesis design approaches. The first type is a pair of rods, each of a suitable stiffness, which are implanted into the corpora cavernosum of the penis. U.S. Pat. No. 3,893,456 is representative of these devices. This approach is disadvantageous for several reasons. The rod has permanent stiffness which could be a source of embarrassment, or pain if the patient attempted to depress the penis in order to conceal it. Additionally, the rod type prosthesis is incapable of appreciably increasing the length or girth of the penis.
The second type of penile prosthesis is of the inflatable variety. The most common of this design includes two long inflatable tubes, or balloons, which are implanted in the corpora cavernosum of the penis. The various two balloon designs include either one or two fluid reservoirs, tubing, valves, and pump to complete the system. The reservoirs and valves are generally implanted in the retropubic space, and the pump in the scrotal sac (U.S. Pat. Nos. 3,853,122; 4,009,711; 4,224,934 and 4,235,227), other designs show them implanted in the abdominal cavity (U.S. Pat. Nos. 3,853,122 and 3,954,102). As a result of the lack of rigidity of the balloons, a large amount of fluid is necessary to pressurize the balloons to obtain the needed degree of penile rigidity, which in turn requires a large reservoir system.
U.S. Pat. Nos. 4,318,396 and 4,353,360 also incorporate the balloon design in a double or single implant configuration, with the fluid reservoir located in the penis as well. In the prosthesis of U.S. Pat. No. 4,318,396, the balloon is made from a rubberized fabric sealed to stiff stem and tip portions at both the proximal and distal ends, respectively. Since the balloon is made of a rubberized fabric there is no appreciable stretching of same when it is pressurized. Further, a magnetic latching clamp is shown which squeezes the prosthesis and the penis over a portion of its length to achieve pressurization of the fluid within to provide the desired erection. This clamp adds unnecessary weight and discomfort to the patient. The prosthesis of U.S. Pat. No. 4,353,360 is a design wherein a first balloon is enclosed within a second balloon with both in communication with an in-line, in-penis valve. These also have the same problems mentioned above for the other balloon type penile prosthesis.
The third type of penile prosthesis is one wherein a rod and a balloon are combined. U.S. Pat. No. 4,201,202 to Finney, et al. shows such a device. However, this design requires the implantation of two separate units each with its own reservoir and valve. The balloon consists of a silicone coated woven fabric around a rod which extends beyond the balloon at both the distal and proximal ends, thereof. This design therefore can only provide expansion axially, not longitudinally, and, the sealing of the balloon with the rod at two locations greatly increases the likelihood of leaks.
In each of the double implant balloon designs a leak in one side will result in erectile pressurization in only one side of the penis. This will yield unsatisfactory performance and a distorted appearance which can only be corrected by another surgery.
It is desirable to have a single implantation design that minimizes the surgery, is inflatable with a small volume of fluid from a single reservoir to minimize the reservoir size, and includes a rod which would provide acceptable performance should the hydraulic portion of the prothesis fail. It is believed that the present invention provides such a device.